Pickup tube for color television



Allg- 1943. A. c. SCHROEDER 2,445,249

PICK-UP TUBE FOR COLOR TELEVISIONS I Filed May 4, 1946 FIG. 2

INVENTOR. Amman c. San-ma ma Patented Aug. 3, 1948 mom was roa coma mansion sures c. Schroeder, Realtor-ville, rs, alsignor tonadiocorporationoldmerionacorporatlon otDelaware mum my 4. 1m. Serhl No. mass This invention relates to targets for color tele-j vision pick-up tubes. Various proposals have been made for such targets in which signals produced by light from a colored object are transmitted either sequentially over one link or slmultaneously over separate links or carriers.

An object or my invention is to provide a targetof special construction tor simultaneous transmission of the signals.

Another object of my invention is to construct a pick-up target with a multiplicity of color filters and signal plates. extending transversely of the direction of line scansion with all the signal plates for a color connected in parallel.

More specifically, an object of my invention is to construct a target or a plurality of small glass or plastic rods of red, green and blue colors, arranged in sequence.

Other objects of the invention will appear from the following description, reference being had to the drawings, in which:

Fig. 1 is an illustration of a small section of one type of target.

Fig. 2 is a side view of the target section of Fig. 1, showing the parallel connections or the signal plates for each color.

Fig. 3 is a perspective view of a small section of a modified form 01- target,

Referring to Fig. 1 of the drawing, the target consists of an insulation plate I, such as thin mica, having a mosaic 2 on one side and a plurality oi strips of color filters on the other side. These may be red, green and blue, 1', g and .b, respectively. arranged in continual sequence from one side of the target to the other and extending transversely oi the direction of line scansion of cathode ray beam 3. n the outside of the color strips are transparent metal conducting strips 4, each acting as a signal plate for the opposite strip oi. mosaic elements. These strips are spaced, or otherwise insulated, from each other. The conducting strips on the filters or one color, e. g., red, are all connected in parallel to a conductor or lead wire extending outside the tube to a transmitting channel; the conducting strips of 4 Claims. (Ol- 250 -184) Another way of securing the same result is shown in Fig. 3. In this modification a plurality of very small wires I are coated with translucent colored sheaths or red, green and blue glass. 1', .q

and b, respectively. The wires 8 may be only a mil or so in diameter and the sheaths may be relatively large to provide paths for the light at each side of the wires. These rods are arranged with the colors in continualsequence, as in Figs. 1 and 2. The wires are the signal plates and wires for red, green and blue are connected in parallel to leads 9, l0 and II, respectively, as in Fig. 2. These leads may all be connected to the ends of the wires at the same side of the target, but preferably two are connected at one side and one at the other, as shown in Fig. 3. On one side of the rods are the mosaic elements 2.

In both embodiments shown, it is preferable that the color filters be sufllciently small to permit the beam spot to encompass at least three filters.

In Fig. 1 light, indicated by arrow L, from the object to be televised in color will be imaged on the mosaic 2 through the transparent metal strips 4, filters r, 9, band mica body I to set up an electrostatic image on the elemental areas of the mosaic in proportion to the colored light focused thereon. In Fig. 3 the light L passes on each side of the wires through the colored sheaths to the mosaic elements on the opposite side of the sheaths..

The electrons of the beam, in landing on the mosaic, produce signals in the usual way, except that at least three signals are formed and transmitted simultaneously, proportional to the red, green and blue light focused on the beam spot. Ways are known for producing a color picture at the receiver, as by a kinescope, from the red," green and blue signals simultaneously transmitted and since this is not a part of the invention claimed, it need not be described.

I claim:

1. A target for color television pick-up tubes comprising a plurality of color filter strips extending across the target, signal strips on one side of said color strips and a mosaic on the other side of said color strips the signal strips of each color strip being connected together and insulated from the others.

2. A target for color television pick-up tubes comprising a plurality of red, green and blue filter strips extending across the target, transparent metal signal strips on one side of the filter strips and a mosaic on the other side of the filter strips, and lead wires connected in parallel strips of each color being connected in parallel.

and a lead wire connected to each group of paraliel-connected signal strips.

4 4. A target for :color television pick-up tubes comprising a plurality of red, green and blue glass rods arranged in color sequence, each rod having a transparent signal strip on one side, a mosaic on the other side of said rods, the signal strips of each color being connected in parallel. and a lead e wire' connected to each group of parallel-connected signal strips.

ALFRED c. SCHROEDER. 

